From: Pascal Paillet <p.paillet@st.com> To: <rui.zhang@intel.com>, <edubezval@gmail.com>, <daniel.lezcano@linaro.org>, <amit.kucheria@verdurent.com>, <mcoquelin.stm32@gmail.com>, <alexandre.torgue@st.com>, <p.paillet@st.com>, <david.hernandezsanchez@st.com>, <horms+renesas@verge.net.au>, <wsa+renesas@sang-engineering.com>, <linux-pm@vger.kernel.org>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org> Subject: [PATCH v2 5/5] thermal: stm32: fix low threshold interrupt flood Date: Mon, 4 Nov 2019 14:30:20 +0100 [thread overview] Message-ID: <20191104133020.8820-6-p.paillet@st.com> (raw) In-Reply-To: <20191104133020.8820-1-p.paillet@st.com> With the STM32 thermal peripheral, it is not possible to dump the temperature that has caused the interrupt. When the temperature reaches the low threshold, we generally read a temperature that is a little bit higher than the low threshold. This maybe due to sampling precision, and also because the CPU becomes hotter when it quits WFI mode. In that case, the framework does not change the trip points. This leads to a lot of low threshold interrupts. The fix is to set the low threshold value 0.5 degrees Celsius below the actual request. The problem is not so frequent with the high threshold and it would no be a good idea to set the threshold value higher than the request. Signed-off-by: Pascal Paillet <p.paillet@st.com> --- drivers/thermal/st/stm_thermal.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/thermal/st/stm_thermal.c b/drivers/thermal/st/stm_thermal.c index 9986716b17c1..f7168762fbde 100644 --- a/drivers/thermal/st/stm_thermal.c +++ b/drivers/thermal/st/stm_thermal.c @@ -324,7 +324,8 @@ static int stm_thermal_set_trips(void *data, int low, int high) if (low > -INT_MAX) { sensor->low_temp_enabled = 1; - ret = stm_thermal_calculate_threshold(sensor, low, &th); + /* add 0.5 of hysteresis due to measurement error */ + ret = stm_thermal_calculate_threshold(sensor, low - 500, &th); if (ret) return ret; -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Pascal Paillet <p.paillet@st.com> To: <rui.zhang@intel.com>, <edubezval@gmail.com>, <daniel.lezcano@linaro.org>, <amit.kucheria@verdurent.com>, <mcoquelin.stm32@gmail.com>, <alexandre.torgue@st.com>, <p.paillet@st.com>, <david.hernandezsanchez@st.com>, <horms+renesas@verge.net.au>, <wsa+renesas@sang-engineering.com>, <linux-pm@vger.kernel.org>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org> Subject: [PATCH v2 5/5] thermal: stm32: fix low threshold interrupt flood Date: Mon, 4 Nov 2019 14:30:20 +0100 [thread overview] Message-ID: <20191104133020.8820-6-p.paillet@st.com> (raw) In-Reply-To: <20191104133020.8820-1-p.paillet@st.com> With the STM32 thermal peripheral, it is not possible to dump the temperature that has caused the interrupt. When the temperature reaches the low threshold, we generally read a temperature that is a little bit higher than the low threshold. This maybe due to sampling precision, and also because the CPU becomes hotter when it quits WFI mode. In that case, the framework does not change the trip points. This leads to a lot of low threshold interrupts. The fix is to set the low threshold value 0.5 degrees Celsius below the actual request. The problem is not so frequent with the high threshold and it would no be a good idea to set the threshold value higher than the request. Signed-off-by: Pascal Paillet <p.paillet@st.com> --- drivers/thermal/st/stm_thermal.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/thermal/st/stm_thermal.c b/drivers/thermal/st/stm_thermal.c index 9986716b17c1..f7168762fbde 100644 --- a/drivers/thermal/st/stm_thermal.c +++ b/drivers/thermal/st/stm_thermal.c @@ -324,7 +324,8 @@ static int stm_thermal_set_trips(void *data, int low, int high) if (low > -INT_MAX) { sensor->low_temp_enabled = 1; - ret = stm_thermal_calculate_threshold(sensor, low, &th); + /* add 0.5 of hysteresis due to measurement error */ + ret = stm_thermal_calculate_threshold(sensor, low - 500, &th); if (ret) return ret; -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-11-04 13:31 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-04 13:30 [PATCH v2 0/5] thermal: stm32: driver improvements Pascal Paillet 2019-11-04 13:30 ` Pascal Paillet 2019-11-04 13:30 ` [PATCH v2 1/5] thermal: stm32: remove hardware irq handler Pascal Paillet 2019-11-04 13:30 ` Pascal Paillet 2019-12-04 21:05 ` Daniel Lezcano 2019-12-04 21:05 ` Daniel Lezcano 2019-11-04 13:30 ` [PATCH v2 2/5] thermal: stm32: fix icifr register name Pascal Paillet 2019-11-04 13:30 ` Pascal Paillet 2019-11-04 13:30 ` [PATCH v2 3/5] thermal: stm32: handle multiple trip points Pascal Paillet 2019-11-04 13:30 ` Pascal Paillet 2019-12-05 10:50 ` Daniel Lezcano 2019-12-05 10:50 ` Daniel Lezcano 2019-11-04 13:30 ` [PATCH v2 4/5] thermal: stm32: improve temperature resolution Pascal Paillet 2019-11-04 13:30 ` Pascal Paillet 2019-12-05 11:03 ` Daniel Lezcano 2019-12-05 11:03 ` Daniel Lezcano 2019-11-04 13:30 ` Pascal Paillet [this message] 2019-11-04 13:30 ` [PATCH v2 5/5] thermal: stm32: fix low threshold interrupt flood Pascal Paillet 2019-11-21 15:42 ` [PATCH v2 0/5] thermal: stm32: driver improvements Pascal PAILLET-LME 2019-11-21 15:42 ` Pascal PAILLET-LME
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